An e-book service is a service that may replace existing paper books and that allows a user to buy or borrow a book the user wants to get at an online bookstore or a mobile app store, and read the book bought or borrowed on a terminal such as a smart phone or a tablet PC. For e-books bought or borrowed through a website, an app store, etc., the patterns of consumption of users managed by a service provider are available for providing a better e-book service.
Recently, as the penetration rates of smart phones and tablet PCs are increasing, even the number of users who use the e-book service is on an increasing trend. In particular, in case of an e-book service using mobile terminals such as smart phones, table PCs, etc., providing customized information including an advertisement for users who subscribe specific e-books may be a very important factor for creating profits for an e-book service provider.
However, the service for providing customized information with e-books so far has been based on the information of e-books bought or borrowed and subscribed by users but has failed to use the relationships formed among multiple users who use e-books. Particularly, the recent trend in multiple users giving as gifts or exchanging a variety of products online including e-books by social networking services whose users are gradually increasing thanks to the penetration of smart phones and tablet PCs has not been reflected on the e-book service.
Accordingly, separate from the simple history of buying or borrowing individuals' e-books, the necessities of technologies to provide optimized and customized information by using human relationships formed through gifts (including a concept of exchange) of e-books among multiple users are on the rise.